2020-10-18日报博客-一周总结

1.学到的东西：

image-20201215131859516

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>login</title>


    <script>
        window.onload = function(){
            document.getElementById("img").onclick = function(){
                this.src="/day16/checkCodeServlet?time="+new Date().getTime();
            }
        }


    </script>
    <style>
        div{
            color: red;
        }

    </style>
</head>
<body>

    <form action="/day16/loginServlet" method="post">
        <table>
            <tr>
                <td>用户名</td>
                <td><input type="text" name="username"></td>
            </tr>
            <tr>
                <td>密码</td>
                <td><input type="password" name="password"></td>
            </tr>
            <tr>
                <td>验证码</td>
                <td><input type="text" name="checkCode"></td>
            </tr>
            <tr>
                <td colspan="2"><img id="img" src="/day16/checkCodeServlet"></td>
            </tr>
            <tr>
                <td colspan="2"><input type="submit" value="登录"></td>
            </tr>
        </table>


    </form>


    <div><%=request.getAttribute("cc_error") == null ? "" : request.getAttribute("cc_error")%></div>
    <div><%=request.getAttribute("login_error") == null ? "" : request.getAttribute("login_error") %></div>

</body>
</html>




package cn.itcast.servlet;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import java.io.IOException;

@WebServlet("/loginServlet")
public class LoginServlet extends HttpServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        //1.设置request编码
        request.setCharacterEncoding("utf-8");
        //2.获取参数
        String username = request.getParameter("username");
        String password = request.getParameter("password");
        String checkCode = request.getParameter("checkCode");
        //3.先获取生成的验证码
        HttpSession session = request.getSession();
        String checkCode_session = (String) session.getAttribute("checkCode_session");
        //删除session中存储的验证码
        session.removeAttribute("checkCode_session");
        //3.先判断验证码是否正确
        if(checkCode_session!= null && checkCode_session.equalsIgnoreCase(checkCode)){
            //忽略大小写比较
            //验证码正确
            //判断用户名和密码是否一致
            if("zhangsan".equals(username) && "123".equals(password)){//需要调用UserDao查询数据库
                //登录成功
                //存储信息，用户信息
                session.setAttribute("user",username);
                //重定向到success.jsp
                response.sendRedirect(request.getContextPath()+"/success.jsp");
            }else{
                //登录失败
                //存储提示信息到request
                request.setAttribute("login_error","用户名或密码错误");
                //转发到登录页面
                request.getRequestDispatcher("/login.jsp").forward(request,response);
            }


        }else{
            //验证码不一致
            //存储提示信息到request
            request.setAttribute("cc_error","验证码错误");
            //转发到登录页面
            request.getRequestDispatcher("/login.jsp").forward(request,response);

        }

    }

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        this.doPost(request, response);
    }
}


package cn.itcast.session;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import java.io.IOException;

@WebServlet("/sessionDemo1")
public class SessionDemo1 extends HttpServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        //使用session共享数据

        //1.获取session
        HttpSession session = request.getSession();
        //2.存储数据
        session.setAttribute("msg","hello session");
    }

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        this.doPost(request, response);
    }
}



package cn.itcast.session;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import java.io.IOException;

@WebServlet("/sessionDemo2")
public class SessionDemo2 extends HttpServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        //使用session获取数据

        //1.获取session
        HttpSession session = request.getSession();
        //2.获取数据
        Object msg = session.getAttribute("msg");
        System.out.println(msg);
    }

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        this.doPost(request, response);
    }
}



package cn.itcast.session;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.*;
import java.io.IOException;

@WebServlet("/sessionDemo3")
public class SessionDemo3 extends HttpServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

        //1.获取session
        HttpSession session = request.getSession();
        System.out.println(session);


        //期望客户端关闭后，session也能相同
        Cookie c = new Cookie("JSESSIONID",session.getId());
        c.setMaxAge(60*60);
        response.addCookie(c);

    }

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        this.doPost(request, response);
    }
}


package cn.itcast.session;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.*;
import java.io.IOException;

@WebServlet("/sessionDemo4")
public class SessionDemo4 extends HttpServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

        //1.获取session
        HttpSession session = request.getSession();
        System.out.println(session);

    }

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        this.doPost(request, response);
    }
}


<%@ page import="java.util.Date" %>
<%@ page import="java.text.SimpleDateFormat" %>
<%@ page import="java.net.URLEncoder" %>
<%@ page import="java.net.URLDecoder" %>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>itcast</title>
</head>
<body>

<%

    //1.获取所有Cookie
    Cookie[] cookies = request.getCookies();
    boolean flag = false;//没有cookie为lastTime
    //2.遍历cookie数组
    if(cookies != null && cookies.length > 0){
        for (Cookie cookie : cookies) {
            //3.获取cookie的名称
            String name = cookie.getName();
            //4.判断名称是否是：lastTime
            if("lastTime".equals(name)){
                //有该Cookie，不是第一次访问

                flag = true;//有lastTime的cookie

                //设置Cookie的value
                //获取当前时间的字符串，重新设置Cookie的值，重新发送cookie
                Date date  = new Date();
                SimpleDateFormat sdf = new SimpleDateFormat("yyyy年MM月dd日 HH:mm:ss");
                String str_date = sdf.format(date);
                System.out.println("编码前："+str_date);
                //URL编码
                str_date = URLEncoder.encode(str_date,"utf-8");
                System.out.println("编码后："+str_date);
                cookie.setValue(str_date);
                //设置cookie的存活时间
                cookie.setMaxAge(60 * 60 * 24 * 30);//一个月
                response.addCookie(cookie);


                //响应数据
                //获取Cookie的value，时间
                String value = cookie.getValue();
                System.out.println("解码前："+value);
                //URL解码：
                value = URLDecoder.decode(value,"utf-8");
                System.out.println("解码后："+value);
                %>
            <h1>欢迎回来，您上次访问时间为:<%=value%></h1>
            <input>

<%



                break;

            }
        }
    }


    if(cookies == null || cookies.length == 0 || flag == false){
        //没有，第一次访问

        //设置Cookie的value
        //获取当前时间的字符串，重新设置Cookie的值，重新发送cookie
        Date date  = new Date();
        SimpleDateFormat sdf = new SimpleDateFormat("yyyy年MM月dd日 HH:mm:ss");
        String str_date = sdf.format(date);
        System.out.println("编码前："+str_date);
        //URL编码
        str_date = URLEncoder.encode(str_date,"utf-8");
        System.out.println("编码后："+str_date);

        Cookie cookie = new Cookie("lastTime",str_date);
        //设置cookie的存活时间
        cookie.setMaxAge(60 * 60 * 24 * 30);//一个月
        response.addCookie(cookie);

%>

        <h1>您好，欢迎您首次访问</h1>
<span></span>

<%
    }

%>

<input>




</body>
</html>

    
    
    <%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>login</title>


    <script>
        window.onload = function(){
            document.getElementById("img").onclick = function(){
                this.src="/day16/checkCodeServlet?time="+new Date().getTime();
            }
        }


    </script>
    <style>
        div{
            color: red;
        }

    </style>
</head>
<body>

    <form action="/day16/loginServlet" method="post">
        <table>
            <tr>
                <td>用户名</td>
                <td><input type="text" name="username"></td>
            </tr>
            <tr>
                <td>密码</td>
                <td><input type="password" name="password"></td>
            </tr>
            <tr>
                <td>验证码</td>
                <td><input type="text" name="checkCode"></td>
            </tr>
            <tr>
                <td colspan="2"><img id="img" src="/day16/checkCodeServlet"></td>
            </tr>
            <tr>
                <td colspan="2"><input type="submit" value="登录"></td>
            </tr>
        </table>


    </form>


    <div><%=request.getAttribute("cc_error") == null ? "" : request.getAttribute("cc_error")%></div>
    <div><%=request.getAttribute("login_error") == null ? "" : request.getAttribute("login_error") %></div>

</body>
</html>

        
        
        <%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>Title</title>
</head>
<body>

    <h1><%=request.getSession().getAttribute("user")%>,欢迎您</h1>

</body>
</html>

2.下周计划:学习Mysql的使用

posted @ 2020-10-18 21:41  巩云龙  阅读(59)  评论(0)  编辑  收藏  举报